Fluid pumps such as centrifugal pumps and vane pumps are well known in the art for their ability to pump fluid from one location and transfer it to another location. These pumps are utilized in many conventional structures, including automobiles. Their use in automobiles includes use as oil pumps, fuel pumps and power steering pumps. These pumps all typically utilize their own housing and have a separate fluid inlet, a fluid outlet and a mechanism for drawing fluid into the inlet of the pump and discharging fluid through the outlet of the pump for delivery to a source.
Many automobile engines utilize one or more balance shafts to minimize any noise, vibration, and harshness ("NVH") generated by the reciprocation of the engine pistons and other engine operations. These balance shafts rotate or counter-rotate within the engine on bearings fed by lubricating oil. These balance shafts are typically located within housings to prevent sump oil from continually flooding the rotating shafts with resultant oil aeration, oil heating, and net losses of engine power. Oil is pumped from an oil pan both to the bearings of the balance shafts and also to the engine, creating an excess of oil within the balance shaft housing. If this excess oil is allowed to build up within the housing, the same problems of aeration of the oil, oil heating, and engine motoring losses will result from repeated contact between the rotating shafts and the residual unscavenged oil.
It is known in the art that discharge openings must be provided to enable the escape of the oil which is fed to the bearings as well as any oil that may have entered the interior of the housing through openings or unsealed joints of the housing. It is also known that the provision of an inlet air opening is beneficial towards creating air flow out of a discharge opening, which in turn aids the flow of discharge oil. Current inlet and discharge openings suffer from a variety of disadvantages in that they do not minimize oil aeration, oil heating, and motoring losses.